MRP weirdness - anyone else see anything like this?


(Gil Violette) #1

Got a part that is planning normally for 2018, but is planning all of 2019’s production to occur before 12/31/2018 - and then bleed off that inventory until rebalancing at zero.

We think it is related to either part setup, or some resource that for some reason, the system thinks cannot run in 2019 - so it moved the production to the first available time period.

Any ideas on what might cause this? Is there a background system function that we may have missed that would prevent scheduling jobs in a particular time period?

Thanks in advance.

(Charlie Smith) #2

My V8 is fuzzy, but is this for one part or are multiple parts doing it?

Charlie Smith

(Gil Violette) #3

One item. Our thinking is that it has something to do with incorrect resource selection (calling out a resource that is not in a resource group, because the routing was copied, but resource group construction changed in the interim).

It doesn’t make sense that it would schedule 2018 find but not 2019, but when the resource group/resource construction doesn’t match, weirdness ensues. Sometimes planned jobs are created but not scheduled, sometimes they are not created at all.

It’s the only avenue I have now, although I’ve reached out to our consultants (Com-Tec in Rochester).

(Charlie Smith) #4

I am assuming the system is creating an unfirm MRP job for 2019? If you remove the unfirm MRP job, what does the time-phase do?

(Rick Stannard) #5

You could also check the Safety Stock, Lot Size and Min/Max records. Values in those fields can affect the planning.

(Gil Violette) #6

As a courtesy, I wanted to update the folks here. The snip below is the details of the issue, and the tested workaround.

I do not know if this problem exists on our system, if it is specific to V8, or if it extends to other versions.

Anyway, here it is.

Description of MPS improper functionality:

When the following conditions exist:

  1. Part has MPS schedule that ends prior to end of planning window (MRP cutoff date)
  2. Sales Order demand exists after last MPS entry date.
  3. MPS buildup does not fully cover demand through end of planning window (MRP cutoff date)
    The following occurs:
    Planned jobs are created to meet all demand to the end of the planning window, and their planned completion date is the date of the last MPS entry.

Workaround is:
For parts that meet the conditions above, build MPS through the planning window at the rate of X per month.